a Department of Sports Sciences , University of Beira Interior , Covilhã , Portugal.
Eur J Sport Sci. 2013;13(5):437-44. doi: 10.1080/17461391.2012.742571. Epub 2012 Nov 13.
The aim of this study was to analyse the relative age effect (RAE) in competitive swimming. The best 50 Portuguese swimmers (12- to 18-year-olds) for the main individual swimming pool events of both genders were considered. Analysis was conducted on 7813 swimming event participants, taking account of respective swimmer birth dates and the Fédération Internationale de Natation points gained. Differences in the distribution of birth dates by quarter year were determined using the Chi-square. A one-way analysis of variance ANOVA was used to test for differences measured in points between individuals by quarterly birth year intervals. A two-way analysis of variance ANOVA was also conducted to test the interaction between gender and seasonal birth date with regard to performance. The results show an inequitable distribution (p<0.01) of birth dates by quarter for almost all age groups and both genders. However, the distribution of birth dates by quarter for each considered swim event shows that RAE seems to exist only for 12-year-old females and 12- to 15-year-old males. Analysing mean swimming performance, post-hoc results (p<0.01) show no consistency in RAE. Higher performance occurs among older swimmers only in 100 m butterfly (female 1998, 1st≠2nd quarter, p=0.003). The results also show no interaction between gender and seasonal birth date (p<0.01). Findings of this study show that a higher number of swimmers, particular males, are born in the first two quarters of the year, although there is mostly no effect of seasonal birth date on performance differences within the top 50 swimmers.
本研究旨在分析竞技游泳中的相对年龄效应（RAE）。考虑了男女主要个人游泳池项目中最好的 50 名葡萄牙游泳运动员（12 至 18 岁）。分析考虑了 7813 名游泳运动员的参赛情况，考虑了各自游泳运动员的出生日期和国际游泳联合会的得分。使用卡方检验确定了按季度划分的出生日期分布的差异。使用单向方差分析（ANOVA）检验了以季度为间隔的个体之间得分的差异。还进行了双向方差分析（ANOVA），以检验性别和季节性出生日期之间在表现方面的相互作用。结果表明，几乎所有年龄组和性别组的出生日期按季度分布都存在不公平现象（p<0.01）。然而，对于每个考虑的游泳项目的出生日期分布表明，RAE 似乎仅存在于 12 岁的女性和 12 至 15 岁的男性中。分析平均游泳表现，事后检验结果（p<0.01）表明 RAE 没有一致性。只有在 100 米蝶泳中，年龄较大的游泳运动员的表现更高（女性 1998 年，1 季度≠2 季度，p=0.003）。结果还表明，性别和季节性出生日期之间没有相互作用（p<0.01）。本研究的结果表明，尽管在 50 名最佳游泳运动员中，季节性出生日期对表现差异的影响不大，但更多的游泳运动员，特别是男性，出生在一年的前两个季度。
